Reaction of (t-Bu2SnO)3 with organohalosilanes.: Simple formation of open-chain and cyclic stannasiloxanes

The synthesis or in situ. formation of the new stannasiloxanes (RRSi)-R-1-Si-2(OSn-t-Bu-2)(2)E (2, R-1 = R-2 = t-Bu, E = O; 22, R-1 = t-Bu, R-2 = F, E = O; 23, R-1 = R-2 = Ph, E = O; 24, R-1 = R-2 = t-Bu, E = S; 25, R-1 = t-Bu, R-2 = F, E S; 26, R-1 = R-2 = Ph, E S), t-Bu2Si[OSn(Cl)-t-Bu-2]2 (3), t-Bu-2(Cl)SnOSi(X)-t-Bu-2 (4,X = Cl; 12, X = H), t-Bu2Sn((OSiRRO)-R-1-O-2)(2)M (5, R-1 = R-2 = t-Bu, M = Sn-t-Bu-2; 7, R-1 = R-2 = Ph, M = Sn-t-Bu-2; 9, R-1 = R-2 = Ph, M = SiPh2; 1.8, R-1 = t-Bu, R-2 = Cl, M = Sn-t-Bu-2; 21, R-1 = t-Bu, R-2 = F, M = Sn-t-Bu-2), t-Bu2Sn(OSiXR2)(2) (10, X = H, R = t-Bu; 11, X = F, R = t-Bu; 13, X = F, R = Et; 14, X = F,R = i-Pr; 15, X = F, R = Ph), t-Bu2Sn(OSiX2-t-Bu)(2) (16, X = Cl; 19, X = Fl, t-Bu2ClSnOSiCl2-t-Bu (17), [R1R2Si(OSn-t-Bu-2)(2)O.t-Bu2SnX2] (20, R-1 = t-Bu, R-2 = F; X = F; 27, R-1 = t-Bu, R-2 = F, X = OR; 28, R-1 = R-2 = Ph, X = OH), O(t-Bu2SnOSiPh2)(2)O (29), t-Bu2Sn(OSiMe2CH2)(2) (30), and t-Bu-2-SnOSiF-t-BuOSn-t-Bu(2)OSit-Bu2O (31) is described. The compounds were characterized by means of multinuclear NMR spectroscopy and Mossbauer spectroscopy. The molecular structures of the eight-membered stannasiloxane rings 5, 7,, 21, and 29 were determined by X-ray analysis, On the basis of NMR and electrospray mass spectrometry a mechanism is proposed involving protonated Species for the redistribution reaction between 5 and 21.